Composición y estructura forestal del Corredor Biológico Interurbano Río Tibás, Heredia, Costa Rica

This research had as objective to determine the forest structure and floristic composition of the “Tibás River Interurban Biological corridor” region. We delimit three elevational zones/strata in the area and established 61 sampling plots (15 x 15 m). Species richness, abundance and ecological group species (early or late-successional and seed dispersal methods) in trees (diameter > 10 cm) and seedlings (individuals between 30 cm and 1.5 m of height) were evaluated. Then we characterized the ecosystems according with diversity indexes (Shannon and Pielou), their diameter category, tree density and forest canopy gap. We recorded 113 tree species in 43 families (diameter > 10 cm) and 122 seedlings species (41 families). Mean tree density estimation ranged between 469- 491 individuals/ha in the elevational zones. The three strata follow a reverse-J diameter distribution, and among 70-77 % of tree diameters ranged between 10 and 39.9 cm. While the three elevational zones recorded optimal recruitment and diversity indexes, according with diameter distribution, Shannon (> 3.13) and Pielou (> 0.81), the low and medium stratum suggested a greater ecosystem disturbance, and less sustainability, due to high earlysuccessional and wind-dispersed species proportions encountered. Likewise, mean forest canopy gap values were moderate in the lower elevational zones (59-72 %) and relatively high in the greater altitudinal level (87 %). This information suggests that the low and medium elevational zones are areas with higher restoration priority, and enrichment strategies in the riparian forest may be required. Se estimó la estructura y composición forestal del área destinada al Corredor Biológico Interurbano Río Tibás. Se delimitó el corredor en tres estratos altitudinales y se realizaron 61 parcelas de muestreo de vegetación (15 x 15 m). Se evaluó la riqueza, abundancia, gremios ecológicos y síndromes de dispersión de árboles mayores o igual a 10 cm a la altura del pecho y brinzales (individuos entre 30 cm y 1,5 m de altura). También se caracterizaron los ecosistemas según índices de diversidad (Shannon y Pielou), categorías diamétricas, densidad de individuos y porcentaje de cobertura vegetal del dosel. Se registraron 113 especies de árboles (43 familias) y 122 de brinzales (41 familias). La densidad de árboles osciló entre 469-491 individuos/ha según el estrato y las categorías diamétricas siguieron una distribución de “J” invertida en las tres zonas altitudinales. Entr